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<p>At the time of the seminar the following papers were unpublished and had a status as follows:  Paper 3: Epubl ahead of print; Paper 5: Manuscript.</p>

To provide some insights on the formation of long-chain carbon-nitrogen bearing ions in Titan’s atmosphere, laboratory measurements of ion-neutral reactions were conducted and results are presented in the following licentiate thesis. The product ions of the C2H2N+ reaction with saturated and unsaturated neutral hydrocarbons have been studied using guided ion beam mass spectrometer (GIB-MS). The data have been used to infer the product ion signal intensity dependences on pressure and collision energies to obtain information on the reactions contributing to these signals. Theoretical calculations have been carried out to interpret these measurements and to elucidate the reaction pathways leading to the observed product ions. This study provides understanding on the formation of long-chain carbon-nitrogen bearing ions through exothermic and barrierless ion-neutral reactions which are of interest as possible formation routes to heavy positive ions detected in Titan’s atmosphere by Cassini’s ion neutral mass spectrometer (INMS).

This project has examined the effects of plasma delay time (PDT) and pulse height defect (PHD) for protons, tritons and alpha particles. The goal was to determine PDT and PHD for alpha particles relative to protons, by using data from a subset of measurements taken with a silicon detector of type PIPS at the LOHENGRIN spectrometer. The PIPS detectors were used in combination with an MCP to measure the time of flight (ToF) of the particles, in addition to their energies. The project involved calibrating energy and time measurements with linear calibration. As a first step, peaks were identified for each particle event in the data set. A Gaussian fit was used to determine the mean value and spread of the peak. Under the assumption that protons have zero PDT and PHD, the proton peaks were used to calibrate all the data with a linear fit. In order to determine the PDT and PHD the real values of ToF and energy for the particles had to be estimated and compared with the measurements. The LOHENGRIN spectrometer gives the real energy of the ions reaching the MCP chamber. The energy losses that occur when using the MCP were estimated with the program SRIM, used to calculate stopping-power and ranges of ions. The real ToF was derived from energy and flight path of the particles. For the flight path measurements of the experimental equipment had to be conducted, partly by the writers of this project and partly by a research team with access to the LOHENGRIN. The result presents the relative PDT and PHD of protons, alpha particles and a triton. The relationship of PDT and PHD to mass and energy is discussed. Notably the PDT was found to depend inversely on the energy of the particle. No definite trend in PHD of alpha particles relative to protons was found, thought to be due to the effect being to small to observe in this study. Empirical formulae from earlier papers were tested to compare with the result of this project. The trend of the results are supported by these formulae.

AbstractThis study is based on a quantitative research, which examines and analyzes the ability of pupils to associate several key abstract and conceptual aspects of maths with reality. First, I analyze aspects of Bruner's theory of three modes of representation. Then I formulate a test model with different tasks, based on the interaction between the current representation forms - enactive, iconic and symbolic. I will use this model to understand where the failure mostly occurs, and the difference between the age groups. Diagnostic tests have been conducted at five different schools during the maths lessons.My main task is to examine the three systems with a quantitative approach, in order to see how the transfer of knowledge between reality, perceptions / images and symbolism. The intention is to investigate how the students observe and create images of things and their phenomena, and perform symbolic operations. At the same time, I will explain the design of tasks for the four important elements such as structure, maturity, initiative, and motives. According to Bruner (1966), the symbolic form is properly developed at the age of ten, and therefore. We had participants from grade one up to grade four and, age seven to ten. Keywords: mathematic, concretization and abstraction, three modes of representation, mathematizing, triad, triadic model, transition, two-way transition, mathematization, manipulative aids. Nyckelord: matematik, konkret och abstrakt, representationsformer, övergångar, tvåvägsövergångar, matematiserande, triad, manipulativa modeller.

Problemet som denna studie fokuserar på är att elever känner att matematik är svår och jobbig. Dessutom tycker ett flertal att många delar i matematiken är onödiga. Syftet med detta arbete är att undersöka om och hur matematikundervisning kan leda till större effektivitet när den ska kopplas till vardagslivet. Denna studie vill även belysa upplevelsers betydelse som ett viktigt perspektiv för lärprocesser. Å ena sidan konkretiserades undervisningen som en grund för ökad kunskapsbildning och å andra sidan medvetandegjordes elever om i vilka sammanhang de kan använda sin kunskap. Resultaten bygger på analys av elevenkät och intervjuer med två legitimerade matematiklärare. Nyckelord: Laboration, upplevelse, varierande undervisning, verklighetsanknytning, yttre faktorer.

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Läroplanens stora tolkningsutrymme och den mångfacetterade betydelsen av kommunikationsförmågan kan antingen bidra till en variation i undervisningen eller en komplexitet om hur förmågan skall tolkas såväl i undervisningen som vid bedömning. Syftet med examensarbetet är att därför att undersöka hur matematiklärare arbetar med kommunikationsförmågan inom matematik så väl under lektionen som i bedömningssyfte och hur relationen mellan undervisning och bedömningen är, med målet att avgöra ifall eleverna får en rättssäker bedömning eller inte. För att svara på frågeställningarna, hur matematiklärare arbetar med kommunikationsförmågan, hur matematiklärare bedömer kommunikationsförmågan och hur står matematiklärares undervisning i relation till bedömning av kommunikationsförmågan, intervjuades sex verksamma matematiklärare som arbetar på tre olika skolor. För att undersöka hur lärarna undervisar och bedömer kommunikationsförmågan antas en fenomenologisk ansats genom semistrukturerade intervjuer, således är det matematiklärarnas beskrivning och tankar kring arbetet med kommunikationsförmågan som är i fokus. Den fenomenologiska ansatsen kombineras med diskursteorin för att beskriva vilken typ av kommunikation som råder i undervisningen och bedömningen. Resultatet indikerar att det råder komplexitet kring såväl undervisningen som bedömningen av kommunikationsförmågan. Det råder olika diskurser beroende av den enskilda matematiklärarnas tolkning av läroplanens beskrivning av förmågan. Det råder även olika diskurser beroende av hur undervisningen planeras vid det aktuella tillfället. De intervjuade matematiklärarna var dock eniga om att kommunikationsförmågan oftast bedöms genom redogörelse av uppgifter skriftligt.

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